Ore-roasting furnace.



1. HARRIS. ORE ROASTING FURNACE.

APPLICATION FILEDJULY 30. 1914.

1,203,613. 'PttGlltGdNOV. 7,1916.

I lug communicates with a different one of JOHN HARRIS, 0F SHEFFIELD,ENGLAND.

ORE-ROASTING summon. '7

Specification of Letters Patent.

Patented Nov. 7, 1916.

Application filed July 30, 1914. Serial No. 854,143.

To all whom it may concern:

Beit known that 1, JOHN HARRIS, a subject. of the King of England,residing at Sheffield, Yorkshire, in England, have invented certain newand useful Improvements in Ore-Roasting Furnaces, of which the followingis a specification. p

This invention relates to 'rabbling appliances for mechanical oreroasting furnaces of the type in which the rabble arms project into theinterior of a hollow shaft longitudinallydivided into channels for theconveyance of the cooling fluid to the arms its ob] ect being to provideimprovements in the means for securing the arms to theshaft and in the,arrangement of pipes for supplying cooling water to the arms by theemployment of which, when the arms are water cooled the shaft itself maybe air cooled with or without a forced draft and any one arm may be moreeasily and quickly removed or'replaced without disturbing any otherparts, while the same fittings may be used to secure, when desired, anair cooled arm to the shaft.

In the accompanying drawings :Figure 1 is a broken vertical section ofthe upper part of a rabble shaft according to this invention. Fig. 2 isa section on the line.

like parts throughout projecting hollow lug B is formed on the .1

shaft for each arm, and the hollow of each the longitudinal channelsformed in the shaft. Only one lug is illustrated the others being ofsimilar construction. v

A transverse hole C is made through the lug-B and intersects one side ofthe hollow therein,

in Figs. 1 and 2. The rabble arm D is provided with a base portion Dwhich approximately fits the hollow of the lug B. One end of the base Dextends into the hollow shaft and the other end is formed with a. flangeD adapted to engage the outward end ofthe.

which is preferably but not necessarily of rectangular cross-section, asshown lug B. A groove D is formed across the base D and 1s so situatedthat when the arm 1s in position it registers with the hole C in thelug. The lower face of the groove 'D 1s slightly tapered as shown inFig. 2

and after the base of the arm has been inserted into the lug a cotter Eof like. taper is driven into the hole C and, engaging the groove Dlocks the arm in place. Preferably the cotter is of less length than thedistance across the lug B so that it is wholly contained therein, bothends of the hole C i being afterward plugged by a suitable refractoryfilling. Although it is preferred that both-the cotter E and the grooveD 'be tapered, one or both of them may have parallel sides if desired.

The lower face of the interior of the hollow lug B conveniently slopesslightly upward from the interior of the shaft to the 'end of the lug,and the base D of the arm D may be provided witha corresponding taper,in order to add to the rigidity of the fastening when the cotter E isdriven into place.

The water cooled arm shown in Figs. 1,

2 and 3 is formed with two cylindrical passages or holes D which extendthrough the armand are closed by any known means such as removableplugs, caps or the like F, the usual feed and discharge water pipesbeing screwed into two separate short holes each communicating with oneof the passages D as indicated in Figs. 1 and 3. At

communicate with. each other as usual to enable the water to circulateand are closed. by removable caps D? or the like. The de tachability ofthe arm from the shaft acts the outer end of the arm the passages D toprolong thelife of the arm in cases where the passages D therein areliable to become choked by depositsof fur from the water; for. as soonas any overheating of the arm or decreased circulation of .water thereinis observed, the arm may be dismounted and, after .the caps F and D? atits ends have been taken ofi, the fur or other deposit may be removed bydrilling through the cylindrical passages D*. I

Cooling water. is fedto the passages D in the arms by pipes G from atank H carried at the top of the shaft A and is discharged through. thepipes J. According to the present invention, however, the feed pipes Gdonot extend continuously from the tank to the arm but are divided aboveor 5 erably the lower portion G is provided with a cupor funnel-likeenlargement Gr into which the upper portion G dips, a tap or valve Gbeing provided on the upper portion to enable, when desired, the waterto be cut off from that feed pipe. The diameter of the pipes G and J andpassages D being not less than'that of the portion G this loose divisionof the feed pipe will not interfere with the circulation of the coolingwater, but it provides simple and effective means for enabling any onearm D to be removed without disturbing any other part or the circulationof water through other arms. To performthis operation the valve G of thearm concerned is closed, the lower portion G of the feed pipe isunscrewed from engagement with the inwardly projecting base D of thearm, and either removed or displaced (the loose division enabling thisto be done most easily), the discharge pipe J may then also be unscrewedand finally the arm D is dismounted by driving back the cotter E from asuitable aperture in the furnace wall. The removal of the cotter is verymuch facilitated by turning the arm D slightly in relation to the shaftin the same direction as that in which it normally moves, this slightmovement of the arm generally loosening the cotter, since theconstruction is such that the resistance to the passage of the armopposed by the ore being treated tends to lock the cotter and hence toincrease the security of its connection to the shaft. The refractoryfilling at the two ends of the hole G preserves the cotter from the daction of the heat and the chemical re actions, and prevents it frombeing fused or otherwise bound irremovably.

A further advantage obtained by the employment of the loose division ofthe feed pipe is that should the water passages D in any arm becomechoked the consequent decrease of circulation will cause the water inthe cup G? or its equivalent to overflow and thus to give a warning ofthe danger before the arm is burned or broken. Hence the arm indicatedmay be removed before it is damaged and its passages cleared after whichit may be used again.

It will be seen that as the Water pipes G and J do notroccupy the wholeof the hollow of the shaft, and as the base parts of the watercooledarms do not block the channels of the shaft into which they extend,

the shaft may itself be air cooled. In order to enable a forced draft tobe used through the shaft, the water tank H ismade annular as shown inFig. 5 surrounding the shaft or an extension thereof and a removablecasing K is provided surrounding the inner wall of the tank, dippingbelow the water therein and leading to suitable means for sucking orforcing air through the hollow shaft as shown diagrammatically at L. Thewater is led from the tank to the arm by 73 a removable bend G passingthrough the shaft or its extension wall, the loose division of the feedpipe in this case being conveniently outside the shaft above the bend GAll the waterpipes inside the shaft are 75 continued to the top of theshaft as shown in Fig. 5 so that they may be easily unscrewed from theirarms, when the casing K has'been removed. The connection of the bend Gwith the feed pipe G need not necessarily be water-tight;- it may be ofthe same type as the loose division hereinbefore described, the bendentering through a suitable aperture in the feed pipe. It is preferredalso to furnish a loose division outside the shaft for ease in removingthe bend, but where such a loose connection between the bend and feedpipe is used it will be seen that in case of choking of the arm passagesthe overflow of water will take 96 place inside the shaft and may bedetected at the bottom thereof.

The improved means of securing arms to the shaft according to thisinvention also enable an air-cooled arm to be substituted for any one ofthe water-cooled arms, Fig. 4; illustrating an air-cooled arm adapted tobe secured to the lug B as hereinbefore described, the end of the armbase being shaped to fit the longitudinal channel in the 0 shaft so asto force the air to circulate through the arm in known manner.

hat I claim and desire to secure by Letters Patent is I 1. In an oreroasting furnace, the combina tion of a hollow shaft having an outwardlyprojecting hollow lug, provided with a transverse passage thatintersects the bore of the lug, a rabble arm having a base approximatelyfitting the interior of the lug, and a locking pin arranged within thetransverse passage in the lug and engaging the arm to secure it to theshaft, the pin being shorter than the passage whereby it is entirelywithin the lug whenin operative position.

2. In an ore roasting furnace, the combination of a hollow shaft havingan outwardly projecting hollow lug, provided with a transverse passagethat intersects the bore of the lug, a rabble arm having a baseapproximately fitting the interior of the lug, a locking'pin arrangedwithin the transverse passage in the lug and engaging the arm to secureit'to theshaft', the pin being shorter than the passage whereby it isentirely within the lug when inoperative position, and a suitablerefractory filling within the ends of said passage.

3. In, an ore roasting, furnace, the combination of a'hollow shafthaving an outwardly projecting hollow lug provided with a transversepassage that intersects the bore of the lug, a rabble arm having a baseapproximately fitting the interior of the lug, and a locking pinarranged within the transverse passage in the lug and engaging the armto secure it to the shaft, the relative position and shape of thepassage and form of the pin being such that the resistance to movementof the arm ofiered by ore being treated acts to increase the lockingaction of the pin on the arm.

4:. In an ore roasting furnace, the combination of a hollow shaft, ahollow arm detachably connected with the shaft, and

means for circulating cooling fluid through the arm including a supplypipe connected at one end with the arm, and comprising a plurality ofsections, the section connected with the arm being adapted to bedetached from the arm independent of any manipulation of any othersection.

5. In an ore roasting furnace, the combination of a hollow shaft, aplurality of hollow arms supported by the shaft, an upwardly extendingpipe connected with each arm and terminating above the upper end of theshaft, and means for supplying cooling fluid to each of said pipes andpermitting any one thereof to be disconnected from the attached armindependent of any adjustment of the others or the fluid supplyingmeans.

6. The combination of a hollow shaft for mechanical ore roastingfurnaces, a rabble arm removably secured thereto, a tank carriedthereby, a sectional feed pipe extending from the tank to'the arm theupper section being fixed to the tank and extending into an enlargementupon the upper end of the lower section near the top of the shaft and areturn pipe from the arm to the exterior of the shaft, substantially asset forth.

7. The combination of a hollow shaft for mechanical ore roastingfurnaces, a rabble arm secured thereto, an annular tank surrounding theshaft, a removable casing surrounding the inner wall of the tank andconnected to means for causing an air current therethrough, feed andreturn pipes extending from the arm within the shaft to ,the topthereof, a removable hollow bend JOHN HARRIS.

Witnesses:

ARTHUR H. GREENWOOD, EDITH A. PORTEUS.-

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. 0.

